1. Field of the Invention
The invention relates to a mechanism for tensioning a belt that transmits power from a power source to cutter blades on a mowing vehicle.
2. Description of the Related Art
Many conventional mowing vehicles provide a mower deck within which blades rotate to cut vegetation. The blades are driven by a belt or series of belts coupled with a power source. These mowers provide mechanisms for tensioning the belt or belts in order to keep them tightly engaged with pulleys coupled to the blades. The tensioners act to compensate for stretching and wear that can occur in the belt over time. Many mower decks roll over the ground surface independent of the vehicle or tractor, such that the tensioners also act to maintain working tension in the belts as the deck moves relative to the vehicle. Many tensioners include a tension spring coupled with a swingable pulley upon which the belt rides. The tension spring pulls the pulley into the belt, thereby placing the belt under tension. The tension in the belt can be released by releasing the tension spring such that the belt can be changed or the mower deck removed. Many mowers do not allow an operator to positively displace the tensioner pulley to facilitate removal of the belt. When the operator pulls the spring to tension the belt he must do a large amount of work to tension the spring to the desired amount.
Many mowers provide two belts: a primary and a secondary belt. The primary belt couples the implement with the power source of the vehicle and has a tension spring and pulley in engagement with the belt. The secondary belt is engaged with the mower blades via a series of secondary pulleys and is also placed under tension by a tensioner pulley and tension spring. One of these secondary pulleys is fixed for rotation with the same shaft as the primary belt's tensioner pulley in order to transmit power from the primary belt to the secondary belt. When an operator releases the primary belt tensioner spring to remove the primary belt, the secondary belt tensioner spring remains engaged. Since the two belts are coupled together by the swingable common shaft of the two pulleys, any tensioning of the secondary belt acts to tension the primary belt even when the primary belt tensioner is released. In order for the operator to remove the primary belt he releases the primary belt tensioner and further pushes the primary pulley by hand to a point where the primary belt becomes slack enough to remove from its pulleys. This may be difficult and awkward due to the position of the primary pulley beneath the vehicle or tractor.
It is known to provide mower decks with handles that can be grabbed by the operator during operation such that the deck can be lifted over ground obstructions without halting mowing operations. These handles are ordinarily welded or otherwise fixed to the deck, which raises the cost to manufacture the deck.